I found this here but it's not working for me since I dont have the code line "" in my code. Is there any other way to do this? Thanks in advance!
To have more then 2 boxes per row, open up the site in SharePoint Designer.
Find the list you wanna edit in SPD, and click on it. From Views on the top right side, click on the boxed listview (may be Allitems.aspx or if you created an additional view called something else).
Then from the top ribbon in SPD, select Design. From Actions, click on Customize XSLT and select Customize entire view.
Find the row and change it to .
Save in SPD and refresh the SharePoint page in the browser where the list exists. Now it should be 4 boxes per row.
Update: To set the width so it display correctly, add a Script Editor WebPart to the page and add this CSS.
<style type="text/css">
table.ms-listviewtable > tbody > tr > td.ms-stylebox {
width: 23,5%;
}
</style>